1. Field of the Invention
The present invention relates to a pneumatic safety tire and more specifically to an improvement in a pneumatic safety tire which enables run-flat travel (run-flat implies a flat punctured tire) with an aspect ratio of a 60% or less (a ratio of height to the maximum width of a tire).
2. Description of the Prior Art
In addition to a strong demand for increased high-speed performance tires with increasing vehicle speed, ultrahigh performance tires which can realize spareless tire or run-flat travel have strongly been required with decreasing vehicle weight.
Requirements for pneumatic safety tires for enabling run-flat travel are as follows:
(a) No cracks will be produced on the boundary between the reinforcing rubber layer and the rim-fixed protruding member during run-flat travel.
(b) A higher load supporting capability is maintained during run-flat travel.
(c) The tire bead portion is not separated from the tire bead seat during run-flat travel.
However, so far there exists no pneumatic safety tire which can satisfy all the above-mentioned requirements.